The dependence of myocardial damage on age and ischemic time in pediatric cardiac surgery

Objective: Heart fatty acid-binding protein is a rapid indicator for assessment of myocardial damage in cardiac surgery. The purpose of this study was to investigate the effects of age and ischemic time on the biochemical evidence and clinical outcomes of myocardial damage in pediatric cardiac surgery. Methods: A prospective observational cohort study conducted over 2.5 years was performed in 98 consecutive patients (51 infants and 47 children) undergoing cardiac surgery for ventricular septal defects. Serial measurements of serum levels of heart fatty acid-binding protein and the respective areas under the curve were obtained, with particular reference to age and aortic crossclamp time. Assessment of clinical outcomes included inotropic support, ventilatory support, and intensive care unit stay. Results: There was a linear dependence of the logarithm of age and the logarithm of heart fatty acid-binding protein release(r = 0.737, P < .0001). This logarithm-logarithm plot showed a power function of age for heart fatty acid-binding protein release. The exponent and amplitude parameter of the power function was the aortic crossclamp time. Compared with children, infants had significantly more myocardial damage and worse clinical outcomes, and these factors were related to the aortic crossclamp time. Conclusions: The younger the age of patients, the more vulnerable are their myocardia to injury caused by ischemia during definitive repair of congenital heart disease. Therefore, perioperative management for pediatric patients after cardiac surgery should be performed, taking into consideration the dependence of the myocardial damage on age and ischemic time.